Stacked multi-channel structure and method for manufacturing same, and thin film transistor comprising same

Abstract

A thin film transistor is provided. The thin film transistor may comprise a stacked channel structure in which a first material layer including an oxide semiconductor and a second material layer including a metal oxide insulator are stacked, wherein the channel structure forms a multi-channel by stacking a plurality of stacks each having the first material layer and the second material layer stacked, and as the number of the stacks stacked increases, mobility and subthreshold swing may increase.

1 . A thin film transistor including a channel structure in which a first material layer including an oxide semiconductor and a second material layer including a metal oxide insulator are stacked,
 wherein the channel structure forms a multi-channel by stacking a plurality of stacks, in which the first material layer and the second material layer are stacked in each of the stacks, and   mobility and subthreshold swing increase as a stacking number of the stacks increases.   
     
     
         2 . The thin film transistor of  claim 1 , wherein an increase rate of the mobility according to the increase in the stacking number of the stacks is higher than an increase rate of the subthreshold swing. 
     
     
         3 . The thin film transistor of  claim 1 , wherein a variation in a threshold voltage is maintained at 10% or less even when the stacking number of the stacks increases. 
     
     
         4 . The thin film transistor of  claim 3 , wherein the threshold voltage is maintained in a range of 0.09 V to 0.19 V even when the stacking number of the stacks increases. 
     
     
         5 . The thin film transistor of  claim 1 , wherein the stacking number of the stacks is greater than equal to 5, and less than or equal to 10. 
     
     
         6 . The thin film transistor of  claim 1 , wherein a thickness of the second material layer is less than 4 nm. 
     
     
         7 . The thin film transistor of  claim 1 , wherein the oxide semiconductor includes indium gallium zinc oxide (IGZO). 
     
     
         8 . The thin film transistor of  claim 1 , wherein the metal oxide insulator includes aluminum oxide (Al 2 O 3 ). 
     
     
         9 . The thin film transistor of  claim 1 , wherein an amount of movement of carriers within the first material layer that is arranged relatively close to a gate is greater than an amount of movement of carriers within the first material layer that is arranged relatively far from the gate. 
     
     
         10 . A method for manufacturing a channel structure, the method comprising:
 preparing a substrate;   forming a first material layer including an oxide semiconductor on the substrate by a plasma-enhanced atomic layer deposition (PEALD) process; and   forming a second material layer including a metal oxide insulator on the first material layer by a PEALD process,   wherein the forming of the first material layer and the forming of the second material layer are alternately repeated so as to form a multi-channel.   
     
     
         11 . The method of  claim 10 , wherein the forming of the first material layer includes:
 reacting an indium (In) precursor, a gallium (Ga) precursor, a zinc (Zn) precursor, and oxygen plasma (O 2  plasma) on the substrate, and   the forming of the second material layer includes:   reacting an aluminum (Al) precursor and oxygen plasma (O 2  plasma) on the first material layer.   
     
     
         12 . The method of  claim 10 , wherein the first material layer and the second material layer are formed by an in-situ process.